Effects of light intensity and food density on the growth and survival of early-stage phyllosoma larvae of the rock lobster Jasus edwardsii

Individual Stage I, III and V phyllosomas of the rock lobster Jasus edwards ii were fed daily with a fixed number (2, 4, 8, 12 or 16) of brine shrimps (Artemia salina, 2-3 mm long) under four different continuous light intensi ties (10, 0.1, 0.001 and less than or equal to 0.0002 mu mol s(-1) m(-2)) t o determine the optimum requirement for growth and survival. Phyllosomas of each stage fed higher rations of brine shrimps had a significantly shorter intermoult period and larger post-moult size. Light intensity had a signif icant effect on the post-moult size of Stage I phyllosomas but had no effec t on the intermoult period. Individual Stage I, III and V phyllosomas were also fed daily with fixed numbers (2, 4 and 8 respectively) of brine shrimp s in containers with different volumes (10, 20, 40, 60, 80, 120 and 240 mL) to alter the prey density while maintaining prey numbers. Prey density had no significant effect on intermoult period or post-moult size but did affe ct consumption rates. The results are discussed in relation to large-scale culture of phyllosoma larvae.